Aside from minor story differentials and details, a major difference includes how the plot is revealed. In the book, Katniss tells the story in first person and how she perceives the world. In the movie, it makes you follow along and make your own judgements on the characters. For example, Haymitch, the mentor to Katniss and Peeta Mallark, is described, in the book, as having passed out in his own vomit from drunkenness. Also, it is clearly stated that he is an alcoholic. In the movie, you only see him passed out and occasionally drinking and it never says he has a drinking problem. You are left to draw that conclusion on your own. In the movie, the key characters are revealed quicker and the plot is developed faster. Whereas, in the book, the story elements emerge at a much slower pace. One minor difference I noticed was that in the book Madges gives Katniss her Mockingjay pin. However, in the movie, the pin is bought off the market, and received before the games by prim, Katniss's little sister.